Hypotonic Labor

Excerpt

Hypotonic labor is an abnormal labor pattern, notable especially during the active phase of labor, characterized by poor and inadequate uterine contractions that are ineffective in causing cervical dilation, effacement, and fetal descent, leading to a prolonged or protracted delivery. Normal labor is divided into three stages, with the first stage typically described in two phases - the latent and active phases. In the active phase, uterine contractions are expected to occur at frequent intervals, increasing the intensity and duration of each contraction. These are deranged in hypotonic labor. Four factors influence the normal progression of labor, denoted as the 4Ps: power (uterine contractions), passage (maternal bony pelvis), passenger (fetus), and fetal presentation. Hypotonic labor is primarily a dysfunction of power; there is inadequate propulsive power to cause fetal descent, cervical dilatation, and eventual expulsion of the fetus(es) and placenta.